How does inventory and availability of a product work ?

Suppose you've 3 inventories of a product. Now if anyone book this product from a02/07/2016 to 04/07/2016, then this product also be available for the next customers in that dates. Because there are still 2 more inventories available in that particular dates. If the next two customers book this product in same dates, then for the fourth customers that dates will be unavailable.